Hydraulic piston pumps handle very large flows at high pressures. They are operated by pistons that move back and forth continuously. The sealing properties of the pistons are excellent, allowing operation at high pressures with low fluid leakage.

Advantages:

• They offer the best overall volumetric efficiency
• They provide the highest pressures
• They are reliable
• They have high power density
• They are available in variable and fixed displacement models

Disadvantages:

• They are the most expensive hydraulic pumps

There are two types of piston mounting: radial mounting and axial mounting.

Axial mounting:

The design of the axial piston pump is based on the swash plate principle or curved shaft design.

• In the case of a swash plate, the rotating pistons are supported by a swash plate; the angle of which determines the piston stroke.
• In the curved shaft configuration, the displacement volume depends on the swivel angle: the pistons move in the cylinders as the shaft rotates.

Radial mounting:

Radial piston pumps are available in two different configurations.

• With an eccentric cylinder block: the piston turns inside the rigid outer ring. The eccentricity determines the stroke of the pistons.
• With an eccentric shaft: the rotating eccentric shaft causes radially oscillating piston movements.

Advantages:

• Radial piston pumps can be equipped with several different independent outputs.